diff --git a/ext/dom/parentnode.c b/ext/dom/parentnode.c
index b7a7cfd07f3..9fdfc7818e8 100644
--- a/ext/dom/parentnode.c
+++ b/ext/dom/parentnode.c
@@ -255,10 +255,33 @@ static void dom_fragment_assign_parent_node(xmlNodePtr parentNode, xmlNodePtr fr
 	fragment->last = NULL;
 }
 
+static zend_result dom_hierarchy_node_list(xmlNodePtr parentNode, zval *nodes, int nodesc)
+{
+	for (int i = 0; i < nodesc; i++) {
+		if (Z_TYPE(nodes[i]) == IS_OBJECT) {
+			const zend_class_entry *ce = Z_OBJCE(nodes[i]);
+
+			if (instanceof_function(ce, dom_node_class_entry)) {
+				if (dom_hierarchy(parentNode, dom_object_get_node(Z_DOMOBJ_P(nodes + i))) != SUCCESS) {
+					return FAILURE;
+				}
+			}
+		}
+	}
+
+	return SUCCESS;
+}
+
 void dom_parent_node_append(dom_object *context, zval *nodes, int nodesc)
 {
 	xmlNode *parentNode = dom_object_get_node(context);
 	xmlNodePtr newchild, prevsib;
+
+	if (UNEXPECTED(dom_hierarchy_node_list(parentNode, nodes, nodesc) != SUCCESS)) {
+		php_dom_throw_error(HIERARCHY_REQUEST_ERR, dom_get_strict_error(context->document));
+		return;
+	}
+
 	xmlNode *fragment = dom_zvals_to_fragment(context->document, parentNode, nodes, nodesc);
 
 	if (fragment == NULL) {
@@ -296,6 +319,11 @@ void dom_parent_node_prepend(dom_object *context, zval *nodes, int nodesc)
 		return;
 	}
 
+	if (UNEXPECTED(dom_hierarchy_node_list(parentNode, nodes, nodesc) != SUCCESS)) {
+		php_dom_throw_error(HIERARCHY_REQUEST_ERR, dom_get_strict_error(context->document));
+		return;
+	}
+
 	xmlNodePtr newchild, nextsib;
 	xmlNode *fragment = dom_zvals_to_fragment(context->document, parentNode, nodes, nodesc);
 
diff --git a/ext/dom/php_dom.c b/ext/dom/php_dom.c
index 662c6e9ef7c..00725d3fb00 100644
--- a/ext/dom/php_dom.c
+++ b/ext/dom/php_dom.c
@@ -1221,10 +1221,15 @@ xmlNode *dom_get_elements_by_tag_name_ns_raw(xmlNodePtr nodep, char *ns, char *l
 {
 	xmlNodePtr ret = NULL;
 
+	/* Note: The spec says that ns == '' must be transformed to ns == NULL. In other words, they are equivalent.
+	 *       PHP however does not do this and internally uses the empty string everywhere when the user provides ns == NULL.
+	 *       This is because for PHP ns == NULL has another meaning: "match every namespace" instead of "match the empty namespace". */
+	bool ns_match_any = ns == NULL || (ns[0] == '*' && ns[1] == '\0');
+
 	while (nodep != NULL && (*cur <= index || index == -1)) {
 		if (nodep->type == XML_ELEMENT_NODE) {
 			if (xmlStrEqual(nodep->name, (xmlChar *)local) || xmlStrEqual((xmlChar *)"*", (xmlChar *)local)) {
-				if (ns == NULL || (!strcmp(ns, "") && nodep->ns == NULL) || (nodep->ns != NULL && (xmlStrEqual(nodep->ns->href, (xmlChar *)ns) || xmlStrEqual((xmlChar *)"*", (xmlChar *)ns)))) {
+				if (ns_match_any || (!strcmp(ns, "") && nodep->ns == NULL) || (nodep->ns != NULL && xmlStrEqual(nodep->ns->href, (xmlChar *)ns))) {
 					if (*cur == index) {
 						ret = nodep;
 						break;
diff --git a/ext/dom/tests/DOMDocument_getElementsByTagNameNS_match_any_namespace.phpt b/ext/dom/tests/DOMDocument_getElementsByTagNameNS_match_any_namespace.phpt
new file mode 100644
index 00000000000..888d1ef9b80
--- /dev/null
+++ b/ext/dom/tests/DOMDocument_getElementsByTagNameNS_match_any_namespace.phpt
@@ -0,0 +1,82 @@
+--TEST--
+DOMDocument::getElementsByTagNameNS() match any namespace
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+/* Sample document taken from https://www.php.net/manual/en/domdocument.getelementsbytagname.php */
+$xml = <<<EOD
+<?xml version="1.0" ?>
+<chapter xmlns:xi="http://www.w3.org/2001/XInclude">
+<title>Books of the other guy..</title>
+<para>
+ <xi:include href="book.xml">
+  <xi:fallback>
+   <error>xinclude: book.xml not found</error>
+  </xi:fallback>
+ </xi:include>
+ <include>
+  This is another namespace
+ </include>
+</para>
+</chapter>
+EOD;
+$dom = new DOMDocument;
+
+// load the XML string defined above
+$dom->loadXML($xml);
+
+function test($namespace, $local) {
+    global $dom;
+    $namespace_str = $namespace !== NULL ? "'$namespace'" : "null";
+    echo "-- getElementsByTagNameNS($namespace_str, '$local') --\n";
+    foreach ($dom->getElementsByTagNameNS($namespace, $local) as $element) {
+        echo 'local name: \'', $element->localName, '\', prefix: \'', $element->prefix, "'\n";
+    }
+}
+
+// Should *also* include objects even without a namespace
+test(null, '*');
+// Should *also* include objects even without a namespace
+test('*', '*');
+// Should *only* include objects without a namespace
+test('', '*');
+// Should *only* include objects with the specified namespace
+test('http://www.w3.org/2001/XInclude', '*');
+// Should not give any output
+test('', 'fallback');
+// Should not give any output, because the null namespace is the same as the empty namespace
+test(null, 'fallback');
+// Should only output the include from the empty namespace
+test(null, 'include');
+
+?>
+--EXPECT--
+-- getElementsByTagNameNS(null, '*') --
+local name: 'chapter', prefix: ''
+local name: 'title', prefix: ''
+local name: 'para', prefix: ''
+local name: 'error', prefix: ''
+local name: 'include', prefix: ''
+-- getElementsByTagNameNS('*', '*') --
+local name: 'chapter', prefix: ''
+local name: 'title', prefix: ''
+local name: 'para', prefix: ''
+local name: 'include', prefix: 'xi'
+local name: 'fallback', prefix: 'xi'
+local name: 'error', prefix: ''
+local name: 'include', prefix: ''
+-- getElementsByTagNameNS('', '*') --
+local name: 'chapter', prefix: ''
+local name: 'title', prefix: ''
+local name: 'para', prefix: ''
+local name: 'error', prefix: ''
+local name: 'include', prefix: ''
+-- getElementsByTagNameNS('http://www.w3.org/2001/XInclude', '*') --
+local name: 'include', prefix: 'xi'
+local name: 'fallback', prefix: 'xi'
+-- getElementsByTagNameNS('', 'fallback') --
+-- getElementsByTagNameNS(null, 'fallback') --
+-- getElementsByTagNameNS(null, 'include') --
+local name: 'include', prefix: ''
diff --git a/ext/dom/tests/DOMElement_append_hierarchy_test.phpt b/ext/dom/tests/DOMElement_append_hierarchy_test.phpt
new file mode 100644
index 00000000000..2d70b10fe9f
--- /dev/null
+++ b/ext/dom/tests/DOMElement_append_hierarchy_test.phpt
@@ -0,0 +1,89 @@
+--TEST--
+DOMElement::append() with hierarchy changes and errors
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom_original = new DOMDocument;
+$dom_original->loadXML('<p><b>hello</b><b><i>world</i></b></p>');
+
+echo "-- Append hello with world --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_hello->append($b_world);
+var_dump($dom->saveHTML());
+
+echo "-- Append hello with world's child --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_hello->append($b_world->firstChild);
+var_dump($dom->saveHTML());
+
+echo "-- Append world's child with hello --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_world->firstChild->append($b_hello);
+var_dump($dom->saveHTML());
+
+echo "-- Append hello with itself --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+try {
+    $b_hello->append($b_hello);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom->saveHTML());
+
+echo "-- Append world's i tag with the parent --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+try {
+    $b_world->firstChild->append($b_world);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom->saveHTML());
+
+echo "-- Append from another document --\n";
+$dom = clone $dom_original;
+$dom2 = new DOMDocument;
+$dom2->loadXML('<p>other</p>');
+try {
+    $dom->firstChild->firstChild->prepend($dom2->firstChild);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom2->saveHTML());
+var_dump($dom->saveHTML());
+
+?>
+--EXPECT--
+-- Append hello with world --
+string(39) "<p><b>hello<b><i>world</i></b></b></p>
+"
+-- Append hello with world's child --
+string(39) "<p><b>hello<i>world</i></b><b></b></p>
+"
+-- Append world's child with hello --
+string(39) "<p><b><i>world<b>hello</b></i></b></p>
+"
+-- Append hello with itself --
+Hierarchy Request Error
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
+-- Append world's i tag with the parent --
+Hierarchy Request Error
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
+-- Append from another document --
+Wrong Document Error
+string(13) "<p>other</p>
+"
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
diff --git a/ext/dom/tests/DOMElement_prepend_hierarchy_test.phpt b/ext/dom/tests/DOMElement_prepend_hierarchy_test.phpt
new file mode 100644
index 00000000000..4d9cf24a618
--- /dev/null
+++ b/ext/dom/tests/DOMElement_prepend_hierarchy_test.phpt
@@ -0,0 +1,89 @@
+--TEST--
+DOMElement::prepend() with hierarchy changes and errors
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom_original = new DOMDocument;
+$dom_original->loadXML('<p><b>hello</b><b><i>world</i></b></p>');
+
+echo "-- Prepend hello with world --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_hello->prepend($b_world);
+var_dump($dom->saveHTML());
+
+echo "-- Prepend hello with world's child --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_hello->prepend($b_world->firstChild);
+var_dump($dom->saveHTML());
+
+echo "-- Prepend world's child with hello --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+$b_world->firstChild->prepend($b_hello);
+var_dump($dom->saveHTML());
+
+echo "-- Prepend hello with itself --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+try {
+    $b_hello->prepend($b_hello);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom->saveHTML());
+
+echo "-- Prepend world's i tag with the parent --\n";
+$dom = clone $dom_original;
+$b_hello = $dom->firstChild->firstChild;
+$b_world = $b_hello->nextSibling;
+try {
+    $b_world->firstChild->prepend($b_world);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom->saveHTML());
+
+echo "-- Append from another document --\n";
+$dom = clone $dom_original;
+$dom2 = new DOMDocument;
+$dom2->loadXML('<p>other</p>');
+try {
+    $dom->firstChild->firstChild->prepend($dom2->firstChild);
+} catch (\DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($dom2->saveHTML());
+var_dump($dom->saveHTML());
+
+?>
+--EXPECT--
+-- Prepend hello with world --
+string(39) "<p><b><b><i>world</i></b>hello</b></p>
+"
+-- Prepend hello with world's child --
+string(39) "<p><b><i>world</i>hello</b><b></b></p>
+"
+-- Prepend world's child with hello --
+string(39) "<p><b><i><b>hello</b>world</i></b></p>
+"
+-- Prepend hello with itself --
+Hierarchy Request Error
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
+-- Prepend world's i tag with the parent --
+Hierarchy Request Error
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
+-- Append from another document --
+Wrong Document Error
+string(13) "<p>other</p>
+"
+string(39) "<p><b>hello</b><b><i>world</i></b></p>
+"
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index 11ab472631b..a4113f954ef 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -390,6 +390,10 @@ static inline void accel_unlock_all(void)
 #ifdef ZEND_WIN32
 	accel_deactivate_sub();
 #else
+	if (lock_file == -1) {
+		return;
+	}
+
 	struct flock mem_usage_unlock_all;
 
 	mem_usage_unlock_all.l_type = F_UNLCK;
diff --git a/ext/opcache/zend_shared_alloc.c b/ext/opcache/zend_shared_alloc.c
index 87bfa2f71f9..befcbe442ab 100644
--- a/ext/opcache/zend_shared_alloc.c
+++ b/ext/opcache/zend_shared_alloc.c
@@ -59,7 +59,7 @@ zend_smm_shared_globals *smm_shared_globals;
 #ifdef ZTS
 static MUTEX_T zts_lock;
 #endif
-int lock_file;
+int lock_file = -1;
 static char lockfile_name[MAXPATHLEN];
 #endif
 
diff --git a/ext/spl/spl_directory.c b/ext/spl/spl_directory.c
index 029edcdfb21..378f707f44c 100644
--- a/ext/spl/spl_directory.c
+++ b/ext/spl/spl_directory.c
@@ -454,7 +454,9 @@ static void spl_filesystem_info_set_filename(spl_filesystem_object *intern, zend
 
 	path_len = ZSTR_LEN(path);
 	if (path_len > 1 && IS_SLASH_AT(ZSTR_VAL(path), path_len-1)) {
-		path_len--;
+		do {
+			path_len--;
+		} while (path_len > 1 && IS_SLASH_AT(ZSTR_VAL(path), path_len - 1));
 		intern->file_name = zend_string_init(ZSTR_VAL(path), path_len, 0);
 	} else {
 		intern->file_name = zend_string_copy(path);
diff --git a/ext/spl/tests/gh11338.phpt b/ext/spl/tests/gh11338.phpt
new file mode 100644
index 00000000000..0a59cea9e74
--- /dev/null
+++ b/ext/spl/tests/gh11338.phpt
@@ -0,0 +1,47 @@
+--TEST--
+GH-11338 (SplFileInfo empty getBasename with more than on slash)
+--FILE--
+<?php
+
+function test($path) {
+    echo "Testing: '$path'\n";
+    $file = new \SplFileInfo($path);
+    var_dump($file->getBasename());
+    var_dump($file->getFilename());
+}
+
+test('/dir/anotherdir/basedir//');
+test('/dir/anotherdir/basedir/');
+test('/dir/anotherdir/basedir');
+test('/dir/anotherdir//basedir');
+test('///');
+test('//');
+test('/');
+test('');
+
+?>
+--EXPECT--
+Testing: '/dir/anotherdir/basedir//'
+string(7) "basedir"
+string(7) "basedir"
+Testing: '/dir/anotherdir/basedir/'
+string(7) "basedir"
+string(7) "basedir"
+Testing: '/dir/anotherdir/basedir'
+string(7) "basedir"
+string(7) "basedir"
+Testing: '/dir/anotherdir//basedir'
+string(7) "basedir"
+string(7) "basedir"
+Testing: '///'
+string(0) ""
+string(1) "/"
+Testing: '//'
+string(0) ""
+string(1) "/"
+Testing: '/'
+string(0) ""
+string(1) "/"
+Testing: ''
+string(0) ""
+string(0) ""